Document exceptions

[denisz1]

MS SDKs typically document which exceptions are thrown.

This is crucial information. We cannot properly handle our error paths without knowing what is going wrong (and catching an Exception tells us nothing).

Many EF Core methods lack complete documentation, because they do not mention exceptions thrown. MSDN was good at this, but the new docs site seems incomplete.

These are the worst culprits:

DbContext.SaveChanges
DbContext.SaveChangesAsync

We cannot rely on the source, because that can change at any time. You need to officially document this.

It's not hard, PLEASE consider this a priority.

(In the meantime, please at least let us know about those two methods.)

[rowanmiller]

Note to self - look for custom exception types that we have defined